Fixation of anions in hydrophilic colloid media

ABSTRACT

Process of mordanting a hydrophilic colloid medium with an addition polymer containing 50-95 mole percent of 2-methyl,5vinyl-pyridinium units or a water-soluble pyridinium salt thereof and the balance of N-aliphatic,2-methyl,5-vinyl-pyridinium units, and a hydrophilic colloid composition containing an acid dye mordanted with such polymer.

United States Patent Daniel Maurice 'llmmerman Mortsel;

August Jean Van Paesschen, Antwerp; Albert Emlel Van Hoot, Berchem, allof [72] Inventors Belgium 121] Appl. No. 810,816

[22] Filed Mar. 26,1969

[45] Patented Nov. 30, 1971 [73] Assignee Gevaert-AGFA N.V.

Mortsel, Belgium [32] Priority Mar. 26, 1968 v [3 3 Great Britain [54]FIXATION OF ANIONS 1N HYDROPHILIC COLLOID MEDIA 11 Claims, No Drawings[52] US. Cl 96/84, 96/1 1,96/57, 260/883, 101/464 [51] Int. Cl G03c 1/84[50] Field of Search 96/57, 84 A, 99; 260/883; 101/464 PrimaryExaminer-J. Travis Brown Attorney-William J. Daniel ABSTRACT: Process ofmordanting a hydrophilic colloid medium with an addition polymercontaining 50-95 mole percent of 2-methyl,S-vinyl-pyridinium units or awater-soluble pyridinium salt thereof and the balance of N-aliphatic,2-methyl,5-vinyl-pyridinium units, and a hydrophilic colloid compositioncontaining an acid dye mordanted with such polymer.

FIXATION F ANIONS IN HYDROPHILIC COLLOID MEDIA This invention relates toa process for fixing anions, e.g. of anionic dyes, in hydrophiliccolloids, and to colloid compositions incorporating polymeric compoundsacting as mordanting agents for anions.

Mordanting agents hindering diffusion of acid dyes in colloid layersstrongly reduce lateral diffusion of said compounds in said layers andare of great interest in the preparation of cinematographic color copiesby the inhibition printing process. 1

In the manufacture of color films according to the inhibition process, afirst step comprises the formation of the relief image suited forabsorbing a dye solution. The relief image is commonly prepared in aphotographic way, e.g., by hardening development of a gelatino-silverhalide emulsion layer and selective removal of the nonhardened portions.The whole is referred to as a matrix or matrix film. The matrixcontaining the relief image after being immersed into a solution of adye is brought into close contact with a colloid layer of a receptormaterial. The receptor material applied for cinematographic purposescontains a transparent film support, at least one colloid layer forabsorbing the dye(s) and occasionally a lightsensitive silver halideemulsion layer. Such material is known as the blank or blank film.

During the contact of the dyed matrix with the blank film, dye absorbedin the relief image of the matrix diffuses into the colloid layer of theblank film, on which in this way a monochrome image is formed. Inrepeating the dye transfer step by using each time a novel blank film,several prints are made with one single matrix. Multicolor images can beobtained by preparing relief images which correspond with the colorseparation images to be reproduced in register. Thus, monochromeseparation images can be printed in register forming on one blank amulticolor image. This process of producing multicolor images byinhibition is described, e.g., by P. Glafkids Photographic Chemistry,Fountain Press, London (1960) Vol. I], 696699. M My In order to improvethe sharpness of the transferred dye images by counteracting lateraldiffusion of the dyes in the colloid layer, mordanting agents areincorporated therein.

For obtaining high quality transfer inhibition prints, the

mordanting agent has to possess a resistivity to diffusion as high aspossible in order to avoid contamination of the matrix. In other words,when a mordanting agent is used, which is insufiiciently resistant todiffusion, some of it passes from the blank upon the matrix. Onreimmersing the matrix in the dye solution, the dye will precipitatealso on nonimage areas and on subsequent printing more or less uniformcolor fog will result on the blank film. This harmful color-fogformation will be repeated and evidently increased during the productionof further prints.

When used in combination with a light-sensitive silver halide emulsionlayer, which is e.g. the case when a silver soundtrack has to beproduced, the mordanting agent has to be of such a type that it does notcause a substantial fog in the lightsensitive silver halide emulsion.

A further requirement for a useful mordant is to effect a sufficientcolor absorption.

By color absorption is meant the maximum color density obtainable in anygiven combination of time and temperature under which the dye-immersedmatrix is brought into close contact with the blank. Said conditions aredetermined by the apparatus ensuring the contact between the matrix andthe blank film.

As mordanting agents more or less successfully meeting the aboverequirements for fixing acid dyes, several groups of polymers containingfree amino groups, tertiary amino groups in salt fonn, or quaternarysalt groups have been proposed.

It has now been found that in colloid compositions a very effectivemordanting action in respect of anionic compounds e.g. acid dyes, can beobtained by the use therein of an addition polymer consisting ofstructural units of the following structural formulas:

Wherein X represents an anion, e.g. a chlorine or methyl sulfate anion,and R an aliphatic radical including a cycloaliphatic and a substitutedaliphatic radical e.g. a C,-C, alkyl radical, preferably a menthylradical.

The ratio of the structural units (A) and (B) in the polymer ispreferably within the ranges 95 to 5 and 50 to 50. For improving thewater solubility of the polymer the structural units represented under(A) can be partly or wholly transformed in salt form.

In order to illustrate the preparation of polymers used according to thepresent invention a detailed preparation recipe is given hereinafter.preparation of 1,2-Dimethyl-5-Vinylpyridinium Methylsulphate In a3-liter reaction flask fitted with a stirrer, a thermometer, a refluxcondenser and a separatory funnel 365 g. of 2- methyl-Swinylpyridinewere dissolved in 1,650 cc. of acetone (dried over magnesium sulfate).The solution was cooled to 3 C.

385 g. of dimethyl sulfate neutralized with potassium carbonate werethen added dropwise to the solution. The quaternization was exothermic.The temperature in the reaction mass was therefore kept between 0 and 10C. by cooling.

As soon as all of the dimethyl sulfate had been added, the temperatureof the reaction mixture was allowed to rise to 20-25 C. and thesuspension of 1,Z-dimethyl-S-vinylpyridinium methylsulphate crystals inacetone was stirred for some 150 minutes more.

Subsequently, the pyridinium salt was filtered, rinsed twice with 150cc. of dry acetone, and dried at room temperature, till the weight ofthe crystals remained constant.

Yield: 690 g. Melting point: 143 C.

Preparation of Copoly[2-Methyl-5Vinylpyridine/1 ,2- Dimethyl-S-Vinylpyridinium Methylsulphate] In a 5-liter reaction flask fittedwith a stirrer, a thermometer, a reflux condenser, and a nitrogengas-inlet tube 900 cc. of 5 N nitric acid were added dropwise withstirring to 536 g. of 2-methyl-5-vinylpyridine. The solution was cooledto 10-15 C.

Subsequently 122.5 g. of 1,2-dimethyl-5-vinylpyridinium methylsulphateand 6.6 g. of potassium persulphate were added to the homogeneoussolution.

A slow nitrogen current was allowed to bubble through the clearsolution. The heating was then started and as soon as the temperature inthe solution reached 75 C., the reaction became exothermic and theheating was switched off.

The temperature rose to C. and solution become more viscous. Then cc. ofwater were added. The temperature again rose to 85 C. and another 150cc. of water were added. In this way the exothermic reaction was beingcontrolled. Up to 750 cc. ofwater (5x150 cc. were added.

After the last addition the reaction was not exothermic anymore. Theheating was switched on again to maintain a temperature of 70 C.

The reaction period was 210 minutes.

The resulting solution was diluted with water to a volume of 3 liters.The pH of the resulting solution was 4.3. While stirring 3.11 of acetoneand 6.21 of dioxan were added thereto. The copolymer precipitated andupon decantation of the supernatant liquid, the residue was washed with1 liter of acetone, then dissolved in water, and diluted with water to avolume of 3 liters.

Yield: 3.1 1 solution (21 percent).

pH of the solution: 4.0.

Intrinsic viscosity [1 ]=l.88 dl. g., measured at 25 C. in aqueous 0.1 Nsodium chloride solution.

The effectiveness in mordanting or diffusion hindering action of thepolymers used according to the present invention is directlyproportional to their intrinsic viscosity [1;].

Acid dyes suited for the inhibition printing process that can bemordanted by means of the polymers and copolymers, the structural unitsof which are given above, are, e.g.:

Fast Red S Conc. (C.I. Acid Red 80C.l. 15,620)

Pontacyl Green SN Ex. (C.I. 44,090)

Acid blue black (C.I. 20,470)

Acid Magenta O (C.I. Acid Violet l9-C.I. 42,685)

Naphthol Green B Conc. (C.l. Acid Green 1-C.l. 10,020)

Brilliant Paper Yellow Ex.Conc. (C.I.Direct Yellow 4-C.l. 24,890)

Tartrazine (C.I. Acid Yellow 23-C.I. 19,140)

Metanil Yellow Conc. (C.I. Acid Yellow 36C.l. 13,065)

Pontacyl Scarlet R Conc. (C.I. Acid Red 89-C.l. 23,910)

Pontacyl Rubine R Extra Conc. (C.I. Acid Red l4-C.l. 14,720)

Suitable supports for the matrix film and the blank film are composed ofmodified cellulose products such as cellulose esters, e.g. cellulosetriacetate, cellulose acetobutyrate, cellulose propionate or syntheticresins such as polycondensation products of the polyester type, e.g.polyethylene terephthalate, polysulphonates and polycarbonates.

Colloids for preparing the receptor layer of blank films containing asilver halide emulsion layer are usually of the same type as those knownto one skilled in the art of preparing photographic silver halidematerials. Normally the colloid layer contains gelatin and/or polyvinylalcohol which colloids may be mixed with coating aids such as wettingagents, polymer latices, viscosity reducers, antistatic agents,softening agents improving the flexibility and-if necessarysome amountof a hardening agent improving the mechanical strength. When used in theproduction of sound film the colloid layer acting as receptor layer inthe blank film is usually applied to a silver halide emulsion layer.

The reason why such structure of the blank film is preferred is thatwhen incorporated into the silver halide emulsion layer most of themordanting polymers, particularly those containing a free amino group,produce a substantial fog in the developed photographic emulsion.Therefore, it is preferred to incorporate the mordanting agent into acolloid layer covering the silver halide emulsion layer, thus preventingdirect contact of the mordanting agent with the light-sensitive silverhalide grains.

When incorporated into a blank film the mordanting polymers andcopolymers containing structural units as described above are preferablyused in an amount of to g. per 100 g. of hydrophilic colloid.

The application of the mordanting polymers used in the present inventionis not necessarily limited to the use as mordants in blanks for theproduction of hydrotype prints. Indeed, the mordanting polymers canequally well be applied for substantially increasing the resistance todiffusion in hydrophilic colloid compositions of most different kinds oforganic substances containing one or more anionic groups. In thatrespect the attention is drawn to their use in combination withcompounds containing an anionic part selected from the group of anioniccolor couplers, anionic masking compounds, and different kinds of dyesused in silver halide photographic materials e.g. anionic colored colorcouplers, antihalation, screening and filter dyes, further anionicantistatic agents, U.V.-absorbing compounds, fluorescing agents andoptical bleaching agents. The said polymers can also be used asdispersing agents in aqueous medium, e.g., for the preparation ofpigment coatings.

So, apart from their use in blank films the mordanting polymerscontaining structural units as described herein are particularlyadvantageously used in the preparation of filter and antihalation layersin photographic silver halide materials. The filter dyes may be applied,e.g., in an antistress layer or in an intermediate layer of a multicolorfilm, which contains normally three differently spectrally sensitivesilver halide emulsion layers. Particulars regarding these specialapplications are disclosed in the United Kingdom Pat. No. 830,189 filedAug. 23, 1957 by Gevaert Photo-Producten N.V.

The said mordanting polymers are further particularly useful to preventthe migration of anionic color couplers in hydrophilic colloids, e.g.gelatin used in silver halide photography.

Color couplers used in silver halide color photography and containingwater-solubilizing groups, e.g. anionic groups such as carboxylic acidor sulfonic acid salt groups, are made more fast to diffusion whenincorporated in the photographic material, e.g. by incorporating intothe molecule of the color coupler a large organic radical, a so-calledballasting group, which is normally an aliphatic radical containing fromfive to 20 carbon atoms in straight line. Nonmigratory color couplersforming on color development with a p-phenylene diamine type colordeveloping agent indophenol or azamethine dyes are described, e.g., byP. Glafkids-Photographic Chemistry-Vol. Il-Fountain Press-London 1960)p. 606-615.

According to the present invention anionic color couplers are made moreresistant to diffusion in a hydrophilic colloid medium by allowing themto adsorb to a mordanting agent as described above.

As a result of the adsorbing or mordanting action of the said additionpolymers the said anionic color couplers produce on color developmentcolor images the sharpness of which is markedly better even if the colorcouplers contain the socalled ballasting group.

The following examples illustrate the present invention.

EXAMPLE 1 To this emulsion layer a colloid layer containing a mordantingagent was applied in a proportion of 3.5 g. of gelatin per sq. m. from asolution containing the following ingredients in parts by weight:

6% aqueous gelatin solution 845 10% aqueous solution of the polymerprepared as described above 125 40% aqueous formaldehyde solution 7.5 2%aqueous solution ofADJUPAL A (a wetting agent containingisononylphenoxypoly(ethyleneoxy),- ethanol sold by Adjuhel N.V.,Belgium) 22.5

The obtained blank film was used in hydrotype printing and yielded verysharp high density color prints.

EXAMPLE 2 Coating solutions of the following compositions were prepared:

inert gelatin g. saponine 2.5 g. 4% aqueous solution of formaldehyde 2.5ml.

amounts of dyestuffs and mordanting polymers in mg. per

sq. m. as indicated in the table below. The pH of the coating solutionswas adjusted to 5.9.

The solutions were coated on separate subbed cellulose triacetatesupports in a proportion of 10 g. of gelatin per sq. m. The dyes are ofsuch nature that they discolor completely in their gelatin layer duringconventional photographic processing.

In the presence of a mordanting polymer applied according to the presentinvention the dyestuffs obtained a high fastness to diffusion, which isneeded in antihalation and filter layers.

The relative diffusion values listed in the table were obtained bycomparing the spectral density obtained in a thick gelatin layer (100times as thick as the colored gelatin layer) after keeping that layer incontact with the difi'erently colored gelatin layers for the same timeunder identical conditions of relative humidity. The values of theoptical densities (one e.g. opacity) being directly proportional to theconcentration of the dyestutf transmitted by diffusion have beencalculated on a procentual basis, the value obtained by the test of acolored gelatin layer containing no mordanting agent and beingidentically colored as those layers containing a mordanting agentaccording to the exemplified preparation being given the arbitrary value100.

The dyestuffs have the following structures:

mots-Q moss-Q We claim:

1. A process of hindering difiusion of anions in a hydrophilic colloidmedium, wherein the diffusion of said anions in said medium is hinderedby a mordanting agent, which is an addition polymer containing 50-95percent structural units having the formulas:

CH (3H N or X l 51 (3H--- CH CH- and the balance of structural unitshaving the formula wherein:

X,and X each represents an anion, and R represents an aliphatic group ora cycloaliphatic group.

2. A process according to claim I wherein the hydrophilic colloid is adye receptor layer in a gelatin-containing blank film.

3. A process according to claim 1 wherein into the hydrophilic colloidis a dye receptor layer of an imbibition-printing receptor materialcontaining 15 to 35 g. of the addition polymer of claim 1 per g. ofhydrophilic colloid.

4. A composition of matter containing a hydrophilic colloid, an organicacid dye compound and as a mordanting agent for said dye an additionpolymer containing 5095 percent of structural units having the formulas:

wherein: X',and X' each represents an anion, and R represents analiphatic radical including a cycloaliphatic radical.

5. A sheet material comprising a support and a layer containing at leastone hydrophilic colloid wherein an addition polymer as described inclaim 4 has been incorporated.

6. A sheet material according to claim 6, which sheet material is ablank film containing a dye receptor layer containing at least onehydrophillic colloid, wherein a mordanting 9. A sheet material accordingto claim 5, comprising a hydrophilic colloid layer containing an anioniccolor coupler and an addition polymer as described in claim 4.

10. A sheet material according to claim 5, comprising a hydrophiliccolloid layer containing an anionic dye and an addition polymer asdescribed in claim 4.

11. A sheet material according to claim 5, containing an anionicantihalation dye, screening dye or filter dye.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,624,229 Dated November 30, 1971 Inventor) Daniel Maurice TIMMERMAN etal It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 6, Claim 4, lines 45-50, in the second formula in these lines,delete II II Column 6, Claim 6, line 1, change "6" to S Signed andsealed this 2nd day of May 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHAIK Attesting Officer Commissionerof Patents tM PC4050 (ID-69) fl u.s. sovnunzn'r rnm'rme OFFICE: lasso-au-su

2. A process according to claim 1, wherein the hydrophilic colloid is a dye receptor layer in a gelatin-containing blank film.
 3. A process according to claim 1, wherein into the hydrophilic colloid is a dye receptor layer of an imbibition-printing receptor material containing 15 to 35 g. of the addition polymer of claim 1 per 100 g. of hydrophilic colloid.
 4. A composition of matter containing a hydrophilic colloid, an organic acid dye compound and as a mordanting agent for said dye an addition polymer containing 50- 95 percent of structural units having the formulas:
 5. A sheet material comprising a support and a layer containing at least one hydrophilic colloid wherein an addition polymer as described in claim 4 has been incorporated.
 6. A sheet material according to claim 6, which sheet material is a blank film containing a dye receptor layer containing at least one hydrophillic colloid, wherein a mordanting agent has been incorporated, which is an addition polymer as described in claim
 4. 7. A sheet material according to claim 5, including a light-sensitive silver halide emulsion layer.
 8. A sheet material according to claim 5, which is a blank film containing a dye receptor layer comprising at least one hydrophilic colloid, wherein a mordanting agent has been incorporated, which is an addition polymer as described in claim 4 and which layer has been applied to a silver halide emulsion layer.
 9. A sheet material according to claim 5, comprising a hydrophilic colloid layer containing an anionic color coupler and an addition polymer as described in claim
 4. 10. A sheet material according to claim 5, comprising a hydrophilic colloid layer containing an anionic dye and an addition polymer as described in claim
 4. 11. A sheet material according to claim 5, containing an anionic antihalation dye, screening dye or filter dye. 